如何在 while 循环之前一劳永逸地提示用户输入？

Question

I'm working on a Python script which takes specific data from a pandas DataFrame called "read_file" and writes it in a csv file. To do so, I'm looping through the rows of the DataFrame until a certain condition is met, and that is when I put the data in a dictionary which I use to update the csv file by using the "to_csv" function. There are surely less broken - and simpler - ways to perform the same thing but I'm leaving optimization for another day (although I'm open to suggestions).

I would like to know if there is a way to prompt the user for a decision regarding the way they want to write the data. Basically, I'm asking them whether they would like to:

1. Overwrite the file and then update it row by row (each time we go through the loop) via the append mode of the to_csv function
2. Not overwrite the file and just append data to it each time the script is run (this means it's getting bigger after a run).

So far my code looks like this:

i = 0
for index, row in read_file.iterrows():
case = row['Case']
first = case.split('-')[0]
second = case.split('-')[1]
third = case.split('-')[2]
fourth = case.split('-')[3]
fifth = case.split('-')[4]
if first == 'X01': # if1
    if second == '01': # if2
        if fourth == '04': # if3
            i += 1
            Ax = float(row['Ax'])
            Ay = float(row['Ay'])
            Az = float(row['Az'])
            ENT = float(row['ENT'])
            Ips = (Ax**2 + Ay**2 + Az**2)**(0.5)
            beta = float(row['beta'])
            date = row['Date'].replace("/", "-")
            totalP = float(row['Total.P'])

            data = pd.DataFrame({'Case': [str(case)],
                'ENT': [ENT],
                'total P': [totalP]},
                index = [i])

            filename = 'curve_{}-{}-{}-{}_I{}-B{}-D{}.csv'.format(first,second,third,fourth,round(Ips, 2),beta,date)
            if os.path.getsize(filename):
                print('Curve file not empty.')
                while True:
                    inp = input('Do you want to: A) Append the file. B) Overwrite the file. [A/B]? : ')
                    if inp in ['A', 'B']:
                        break
                if inp == 'A':
                    print('Appending... ')
                    data.to_csv(filename, mode='a')
                elif inp == 'B':
                    print('Overwriting... ')
                    data.to_csv(filename, mode='w')

However this prompt appears each time the conditions if1, if2 & if3 are met, which is quite often. Is there a way to only specify the input once and for all?

Thanks

---

EDIT:

A sample file would be:

Case	Date	ENT	beta	Ay	Ax	Az	Total.P
X01-01-ARK-03-001	09/04/21	0	0,193648827	0	15	10	3354
X01-01-ARK-03-002	09/04/21	3	0,000183247	0	19	12	813
X01-01-ARK-03-003	09/04/21	6	0,491674971	0	14	0	4111
X01-01-ARK-03-004	09/04/21	9	0,757163602	0	1	5	2829
X01-01-ARK-03-005	09/04/21	12	0,622608381	0	44	11	143
X01-01-ARK-03-006	09/04/21	14	0,543299744	0	34	3	4732
X01-01-ARK-03-007	09/04/21	15	0,624404717	0	16	9	3052
X01-01-ARK-03-008	09/04/21	16	0,977021142	0	23	9	2178
X01-01-ARK-03-009	09/04/21	17	0,97697958	0	3	12	191
X01-01-ARK-04-001	09/04/21	0	0,440339098	0	33	9	1472
X01-01-ARK-04-002	09/04/21	3	0,982879346	0	49	2	253
X01-01-ARK-04-003	09/04/21	6	0,740821012	0	27	5	4100
X01-01-ARK-04-004	09/04/21	9	0,48267087	0	38	0	3582
X01-01-ARK-04-005	09/04/21	12	0,578068153	0	45	11	3320
X01-01-ARK-04-006	09/04/21	14	0,541974323	0	41	0	2064
X01-01-ARK-04-007	09/04/21	15	0,445777405	0	22	6	435
X01-01-ARK-04-008	09/04/21	16	0,263795323	0	27	10	1251
X01-01-ARK-04-009	09/04/21	17	0,708550336	0	44	12	60

and the expected output is:

index	Case	ENT	Total.P
1	X01-01-ARK-04-001	0	1472
2	X01-01-ARK-04-002	3	253
3	X01-01-ARK-04-003	6	4100
4	X01-01-ARK-04-004	9	3582
5	X01-01-ARK-04-005	12	3320
6	X01-01-ARK-04-006	14	2064
7	X01-01-ARK-04-007	15	435
8	X01-01-ARK-04-008	16	1251
9	X01-01-ARK-04-009	17	60

Answer 1

Ask the user the question before you iterate over the file, this way the question is only asked (and answered) once:

while True:
    inp = input('Do you want to: A) Append the file. B) Overwrite the file. [A/B]? : ')
    if inp in ['A', 'B']:
        break

i = 0
for index, row in read_file.iterrows():
case = row['Case']
first = case.split('-')[0]
second = case.split('-')[1]
third = case.split('-')[2]
fourth = case.split('-')[3]
fifth = case.split('-')[4]
if first == 'X01': # if1
    if second == '01': # if2
        if fourth == '04': # if3
            i += 1
            Ax = float(row['Ax'])
            Ay = float(row['Ay'])
            Az = float(row['Az'])
            ENT = float(row['ENT'])
            Ips = (Ax**2 + Ay**2 + Az**2)**(0.5)
            beta = float(row['beta'])
            date = row['Date'].replace("/", "-")
            totalP = float(row['Total.P'])

            data = pd.DataFrame({'Case': [str(case)],
                'ENT': [ENT],
                'total P': [totalP]},
                index = [i])

            filename = 'curve_{}-{}-{}-{}_I{}-B{}-D{}.csv'.format(first,second,third,fourth,round(Ips, 2),beta,date)
            if os.path.getsize(filename):
                print('Curve file not empty.')
                if inp == 'A':
                    print('Appending... ')
                    data.to_csv(filename, mode='a')
                elif inp == 'B':
                    print('Overwriting... ')
                    data.to_csv(filename, mode='w')